Serology for brucellosis is a blood test to look for the presence of antibodies against Brucella. This is the bacterium that causes the disease brucellosis.
Brucella serology; Brucella antibody test or titer
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
There is no special preparation.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
Brucellosis is an infection that occurs from coming into contact with animals that carry Brucella bacteria.
Your doctor may order this test if you have signs or symptoms of brucellosis. People working in jobs where they often come in contact with animals or meat, such as slaughterhouse workers, farmers, and veterinarians, are most likely to get this disease.
A normal (negative) result usually means you have not come in contact with the bacteria that causes brucellosis. However, this test may not detect the disease at an early stage. Your doctor may have you come back for another test in 10 days to 3 weeks.
Infection with other bacteria, such as Yersinia, Francisella, and Vibrio, and certain immunizations can cause false-positive results.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal (positive) result usually means you have come in contact with the bacteria that causes brucellosis.
However, this positive result does not mean that you have an active infection. Your doctor will have you repeat the test after a few weeks to see if the test result increases. This increase is more likely to be a sign of a current infection.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Hall GS, Woods GL. Medical bacteriology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 57.
Young EJ. Brucella species. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 226.
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.